It is an accepted and common procedure in a microbiology laboratory to spread a sample over a nutrient agar surface to obtain isolated colonies of growth. After incubation, a colony is selected for further studies and transferred to sterile nutrient broth. This transfer is normally accomplished by employing a straight wire or loop attached to a suitable handle, sterilized in a Bunsen burner, and cooled. A portion of the wire tip is touched or embedded within the colony and adhering bacterial cells released from the straight wire or loop by (1) inserting the wire in a tube of nutrient broth and vigorously flicking the wire from one side of the tube to the other, or (2) touching the wire or loop tip to the side of the tube and washing the cells off the tube wall with nutrient broth. Although previously not practical, in applicant's referenced prior application, the transfer straight wire was allowed to remain in the tube of nutrient broth during incubation.
The wire probe used to sample the colony in applicant's referenced prior invention acts very much like the previously employed straight or loop transfer wire in the laboratory. However, a major difference in applicant's system is that movement of cells adhering to the wire probe relies on the movement of broth over the probe by the pulling action of the plunger within the syringe barrel. Cells not freed by this action remain as a locus of growth at or near the tip of the pipette.
It is an object of the present invention to provide an improved pipette-syringe combination that can also serve as a growth chamber for the collected sample.
Another object of the present invention is an improved pipette-syringe sampling system that increases the efficiency of collecting, releasing, and dispersing cells within the pipette over that attained by a conventional wire or loop sampler.
An additional object of the present invention is an improved sampling probe that contacts and retains more of a bacterial culture growth than previously employed sampling probes.
A further object of the present invention is a process of obtaining a representative bacterial sample on and within a tubular sampling probe, positioning the sample containing probe in a pipette, adding and sealing a quantity of nutrient broth in the pipette, and incubating the sample in the nutrient broth containing pipette before transferring the accumulated culture growth to a number of tubes.